Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

CVE-2026-74716

Gravedad:
Pendiente de análisis
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
22/08/2026
Última modificación:
22/08/2026

Descripción

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> accel/amdxdna: Fix locally exploitable BUG_ON in amdxdna_insert_pages()<br /> <br /> In amdxdna_insert_pages(), vm_flags_mod() sets VM_MIXEDMAP and clears<br /> VM_PFNMAP. If an unprivileged userspace process mmaps a non-imported GEM<br /> object and then calls madvise(MADV_DONTNEED), the PTEs will be<br /> successfully cleared because VM_MIXEDMAP allows this (unlike VM_PFNMAP).<br /> <br /> When userspace subsequently accesses the memory, drm_gem_shmem_fault()<br /> handles the page fault and attempts to map the backing shmem page via<br /> vmf_insert_pfn() which calls vmf_insert_pfn_prot(). Because the backing<br /> shmem page is normal system memory (pfn_valid(pfn) is true) and the VMA<br /> now has VM_MIXEDMAP set, won&amp;#39;t this predictably trigger the explicit<br /> assertion BUG_ON((vma-&gt;vm_flags &amp; VM_MIXEDMAP) &amp;&amp; pfn_valid(pfn))<br /> <br /> Fix by removing the vm_flags_mod() call and replacing the vm_insert_pages()<br /> pre-population with the handle_mm_fault() loop that was already used for<br /> the import (dma-buf) path.

Impacto